Effects of Annealing and Neutron Irradiation on Micostructural and Mechanical Properties of High Burn-up Zr Claddings

고연소도 신형 Zr피복관의 미세조직과 기계적 특성에 미치는 열처리 및 중성자 조사의 영향

  • Baek, Jong Hyuk (Zirconium Fuel Cladding Team, Korea Atomic Energy Research Institute) ;
  • Kim, Hyun Gil (Zirconium Fuel Cladding Team, Korea Atomic Energy Research Institute) ;
  • Jeong, Yong Hwan (Zirconium Fuel Cladding Team, Korea Atomic Energy Research Institute)
  • 백종혁 (한국원자력연구소 지르코늄신합금 핵연료피복관 개발팀) ;
  • 김현길 (한국원자력연구소 지르코늄신합금 핵연료피복관 개발팀) ;
  • 정용환 (한국원자력연구소 지르코늄신합금 핵연료피복관 개발팀)
  • Received : 2004.03.10
  • Accepted : 2004.04.28
  • Published : 2004.05.30

Abstract

The changes of microstructural and mechanical properties were evaluated for the high burn-up fuel claddings after the neutron irradiation of $1.8{\sim}3.1{\times}10^{20}n/cm^2$ (E>1.0 MEV) in HANARO research reactor. After the irradiation, the spot-type dislocations (a-type dislocations) were easily observed in most claddings, and the density of the dislocations was different depending on the grains and was higher at grain boundaries than within grains. As the final annealing temperature increased, the density of spot-type dislocations increased and the line-type dislocations (c-type dislocations) which was perpendicular to the <0002> direction, appeared sporadically in some claddings. However, the types of precipitates in the fuel claddings after the irradiation were not changed from that in unirradiated claddings. The mechanical properties including the hardness, strength and elongation after the irradiation were changed due to the formation of spot-type dislocations. That is, the increase in hardness and strength as well as the decrease in elongation after the irradiation was occurred simultaneously with increasing the final annealing temperature. Owing to the Nb contribution to the formation of spot-type dislocation during the irradiation, the increase in hardness and strength in higher Nb-contained Zr alloys after the irradiation was higher than that in lower Nb-contained Zr alloys.

Keywords

Acknowledgement

Supported by : 과학기술부

References

  1. K.S. Lee, Introduction to Nuclear Fuels, Korea (2001)
  2. K.S. Lee, Irradiation Engineering of Nuclear Fuel and Materials, Korea (1997)
  3. S.J. King, R.L. Kesterson, K.H. Yueh, R.J. Comstock, W. M. Herwig, and S. D. Ferguson, Zirconium in the Nuclear Industry, ASTM STP 1423 (2002) 471
  4. R.J. Comstock, G. Scheonberger, and G. P. Sabol, Zirconium in the Nuclear Industry, ASTM STP 1295 (1996) 710
  5. G.P. Sabol, R.J. Comstock, R.A. Weiner, P. Larouere, and R.N. Stanutz, Zirconium in the Nuclear Industry, ASTM STP 1245 (1994) 724
  6. G.S. Sabol, G.R. Kilp, M.G. Balfour, and E. Robert, Zirconium in the Nuclear Industry, ASTM STP 1023 (1989) 227
  7. R.J. Comstock, Seminar Materials on Optimized ZIRLO for Next Generation Fuel, Nov. 4, Korea (2003)
  8. P. Bossis, J. Thomazet, and F. Lefebvre, Zirconium in the Nuclear Industry, ASTM STP 1423 (2002) 190
  9. J.-C. Brachet, L. Portier, T. Forgeron, J. Hivroz, D. Hamon, T. Guilbert, T. Bredel, P. Yvon, J.-P. Mardon, and P. Jacques, Zirconium in the Nuclear Industry, ASTM STP 1423 (2002) 673
  10. J.-P. Mardon, D. Charquet, and J. Senevat, Zirconium in the Nuclear Industry, ASTM STP 1354 (2000) 505
  11. T. Isobe and Y. Matsuo, Zirconium in the Nuclear Industry, ASTM STP 1132 (1991) 346
  12. T. Isobe, Y. Matsuo, and Y. Mae, Zirconium in the Nuclear Industry, ASTM STP 1245 (1994) 437
  13. S.K. Kim, J.Y. Park, and Y.H. Jeong, J. Kor. Inst. Met. & Mater., 42(1) (2004) 7
  14. K.N. Choo, M.S. Cho, J.M. Oh, Y.T. Shin, Y.H. Kang, I.C. Im, and S. R. Hwang, Proceedings on Korean Nuclear Society 2003 Fall Meeting, (2003)
  15. ASTM E8-00, Standard Test Methods for Tensile Testing of Metallic Materials, (2000)
  16. D.O. Northwood, Atomic Energy Review, 154 (1977) 547
  17. R.B. Adamson, Zirconium in the Nuclear Industry, ASTM STP 1354 (2000) 15
  18. R.A. Holt and R.W. Gilbert, J. Nucl. Mater., 137 (1986) 185
  19. M. Griffiths and R.W. Gilbert, J. Nucl. Mater., 150 (1987) 169
  20. M. Griffiths, R.W. Gilbert, V. Fidleris, R.P. Tucker, and R.B. Adamson, J. Nucl. Mater., 150 (1987) 159
  21. Y. de Carlan, C. Regnard, M. Griffiths, D. Gilbon, and C. Lemaignan, Zirconium in the Nuclear Industry, ASTM STP 1295 (1996) 638
  22. R.W. Gilbert, M.A. Griffiths, and G.J.C. Carpenter, J. Nucl. Mater., 135 (1985) 265
  23. W.J.S. Yang, R.P. Tucker, B. Cheng, and R.B. Adamson, 138 (1986) 185
  24. A. Motta and C. Lemaignan, J. Nucl. Mater., 195 (1992) 277
  25. M. Griffiths, R.W. Gilbert, G.J.C. Carpenter, J. Nucl. Mater., 150 (1987) 53
  26. H.G. Kim, J.H. Baek, M.H. Lee, Y.B. Chun, and Y.H. Jeong, J. Kor. Nucl. Soc., 35(5) (2003) 471
  27. V. N. Shishov, A.V. Nikulina, V.A. Markelov, M.M. Peregud, A.N. Kozlov, S.A. Averin, S.A. Kolbenkov, and A.E. Novoselov, Zirconium in the Nuclear Industry, ASTM STP 1295 (1996) 603
  28. D. Gilbon, A. Soniak, S. Doriot, and J.-P. Mardon, Zirconium in the Nuclear Industry, ASTM STP 1354 (2000) 51
  29. S.A. Averin, V.L. Panchenko, A.V. Kozlov, L.P. Sinelnikov, V.M. Shishov, and A.V. Nikulina, Zirconium in the Nuclear Industry, ASTM STP 1354 (2000) 105